Pneumatic hammer



mvmm

Patented Sept. 20, 1921.

w M 2 m mm W A A. BAILLY.

PNEUMATIC HAMMER.

7 APPLICATION FILED JULY], 1920- ...H TF

the cylinder.

UNITED STATES PATENT OFFICE.

ARMAND BAILLY, OF PARIS, FRANCE.

PNEUMATIC HAMMER.

Specification of Letters Patent. Pat t s tgo, 1 21 Application filed July 7, 1920. Serial No. 394,591.

' (GRANTED mums m raovzsronsor rim ACT or xancn a, 1921, 41 star. 1., 131:.

. Henri IV,)'have invented a new and useful Pneumatic Hammer, (for which I have filed application in- France Apr. 19, 1919, Patent 495,774,) which improvements are fully set forth in the following specification.

This invention relates to a pneumatic hammer characterized by a distribution which enables a hammer to be economically worked by compressed air,further to a movable ring construction which, during accidental withdrawal of'the tool, avoids the 1mparting of any injurious shocks to the piston at the end of itstravel; the whole being completed, by a stop-cap for the tool, which sto -cap is easily detachable.

n embodiment of'the invention is illustrated by way of example in the accompanying drawing.

Figure 1 shows in elevation and in longitudinal section the general arrangement of the hammer with the piston at the end of the left hand stroke. v

Fig. 2.-is a view of the cylinder cover with the exhaust pipe;

Fig. 3 is a partial section of the cylinder, showing'the piston at the end of the right Fig. 4 is a side view of the front part of Fig. 5 shows tion.

Fig. 6 is an end view of the stop-cap. Fig.7 is a sectional view, of the stop-cap.

and

Fig. 9 is a sectional view of the safety ring,-with a part of the cylinder and the piston. The apparatus comprises as usual in apparatus of this kind, a handle a screwed on one end of a cylinder b in which travels the striking piston c.which strikes the tool e;

said handle thus embodying 'a'portion'which forms a cover or closure v end, as will be understood from Figs.'1 and 2.

With the ri I engages partia ly a tubeJc intended for the escape of the air whichhas done its work.

The compressed air is admitted through the same part in front eleva-' Fig. 8 is an end view of the safety ring, 7

or said cylinder ht hand part of the piston.

the opening f of the cylinder; this admiss1on is regulated by hand by means of a cock of any of the usual types.

The air admitted through opening f into the chamber 9 acts on the annular shoulder on the piston and pushes the latter to the right; when the piston uncovers the opening provided at h in the ,wall of the cylinder,

the compressed air can pass to the other side of the piston and act on its right face I which stops the movement of the piston (Fig. 3), then starts it to the left.

In this movement toward the left, the part d of the, piston first closes the port h, which stops the admission of compressed air to the right hand face of the piston; the piston, under the action of expansion of the air, continues to travel until its face I uncovers the end m of the exhaust tube k, as shown in he air escapes therefore through the central opening n of the tube It and then through the radiating holes 0 which are formed in the cover portion of the handle and open at their outer ends into an annular space 9 in the handle, the holes 0 intersecting at their inner ends in a common point. The space 9 encircles the aforesaid cover portion, and

from it extend the outlet openings q for discharging the air into the atmosphere. Other,

shapes of conduits could be used for leading the exhaust air into the atmosphere.

After the exhaust, the piston strikes the tool 6, stops and rebounds, and the air continuing to pass through opening f to its annular shoulder, causes it to begin again the same cycle, and soon.

- The characteristic feature of this'distribution is the use of the central tube Irwhich makes it'possible to regulate the moment of opening of the exhaust where it may be cons dered necessary, in order to obtain suflicient admlssion and sufficient expanslon of the air which are generally obtained only by the use of a comparatively delicate part such as a slide or other valve, whereas the exhausttube used here, is a fixed and strong part.

At the left hand end of the cylinder is the tool e on which the piston strikes. This toolis set in a ring 5 provided with special open ings, the function of which is as follows:

11 normal working, the air contained in the chamber r between the piston and the 1 result is strengthened by the closing of the tool, escapes from the cylinder and freely renters it at each reci rocation of the piston through the conduits t and the holes a provided in the ring a, and then through the groove '0 and the holes to provided in the endof the c linder b.

The oles w open under the envelop formed by the cylindrical part of the stop A so as not to be exposed direct to the dust of the atmosphere.

As soon as the tool e ceases for any reason to be pressed toward the ri ht, it moves to the left under the action 0 the piston and carries with it the ring 8, which results'in covering the outlet holes a and the groove v, as shown clearly in Fig. 9; at this moment the air contained in the chamber 1' can no longer escape, and hence it is compressed and stops the piston before the latter strikes the-cylinder at the end of its stroke. This passage f for the admission of air to the cylinder; infect, the movement to the left of the tool and of the ,ring enables the part d of the piston to cover again the port I for the admission of compressed air, an the compression of the air contained in the closed space 9 contributes to stopping. the piston as the latter moves toward the left (see Fig. 9).

The stoppage toward the right is roduced, in itsturn, by the compression of the air in the closedspace contained between the face I of the piston and the part i when the part d of the piston covers and passes beyond the port j.

The stop-cap A which prevents the tool from coming out, must be easily detachable while offering no risk of becomin detached from the cylinder durin the wor ing.

This object is attainedy the system shown in detail in Figs. 3-7. The end of the cylinder has a series of equidistant thickened gortions D, each provided with a recess etween the said thickened ortions D are left free passages C; througv the said passages C can pass tenons B arran d in the interior of the cap A to the num r corresponding to that of the passages C.

' 'Duringthe movement of introduction by hand of the cap A on the cylinder'b, the spring F is compressed; thereupon, the cap bemfi sufliciently engaged to bring the tenons into thefree s ace G, the ca A is turned about the cylin er b, so as to p ace thetenons 'B op osite the recesses E, then 'xthe capfA is re eased and brought by the thrust of the spring E into the working position shown in Fig. 1.

Reverse movements enable the ca A to be easily removed. During the wor mg of the hammer, the spring F keepsthe tenons D in enga ement with the recesses E. The number of made greater or less at will.-

The system of safety ring and stop cap described'need notnecessarlly form an inseparable part of the hammer described. They could be separated from it and fitted together or separately to otherconstructions' of pneumatic hammer in which their use ma be considered advisable.

claim as my invention:

the tenons and of the recesses is 1. In a hammer, the combinationof a cylinder; a handle connected to one end of the c linderand provided with a central disc arg tube for the spent motive fluid and with ducts leading from said tube to the atmosphere, said tube extending into the interior' of the cylinder; a reci rocating percussive piston in said cylin er having an inwardlysextending recess in its rear end to receive said tube; means for supplying motive fluid-under pressure across the cylinder; an annular shoulder on the rear portion of the piston to be acted on by said fluid; and a ductin the wall of the c linder' for-bypassing the fluid from one si e of said shoul der to the other.

2. In a hammer, the combination of a cylinder; a handle connected to one end of the cylinder and embodying a cover for said cylinder end formed internally with a plurality of radiating outlet holes which intersect attheir inner ends at a common point and open at their outer ends through the.

shoulder on the rear dportion of the piston to be acted on'by sai fluid; and a duct in the wall of the cylinder for by-passing the fluid from one side of said shoulder to the other.- 1

In testimony whereof I have signed this specification inthe presenceof two subscribing witnesses.

. Witnesses: FERNAND Durorm,

CLEMENT S. Eowanns.

'ARMAND BAILLY.1

ormed with an annular space encircling 

